Two-stroke sleeve-valve internal combustion engine of the liquid fuel injection compression ignition type



March 26, 1935. R RlCARDo 1,995,57

Two-STROKE SLEEVE VALVE INTERNAL COMBUSTION ENGINE OF THE LIQUID FUELINJECTION COMPRESSION IGNITION TYPE Filed. April 1, 1955 I-NVENTO'RPatented Mar. 26, i935 i UNiTEl) sTATEs PATELN T OFFICE? .TIOhTTYBEHarry Ralph-Ricardo, London,

Application aim-n .1, weasel-m No. 664,040

In Great Britain April 20, 1932 9 Claims. (cues-s1 This inventionrelates to internal combustion engines of the liquid fuel injectioncompression ignition'type operating on the two-stroke cycle whereininlet ports in the cylinder wall are con- 5 trolled by one or moresleeve valves and the .air

charge enters the cylinder in such a manner as to cause rotation of thischarge about the cylinder ams i'or the purpose offacilitating theadmixture of fuel and air during the'iuelinjection and combustionprocess.

-'In engines of the above type as generally made:

the scavenging air entering through ports in the cylinder wall isdeflected so as to enter the cylinder tangentially by means of bailiesformed in or attached to thiscylinder wall and while the ports in thesleeve are normally shaped so as not to impede this'tangential entrymore than-can be avoided, yet owing to the thinness oi the part '.of.the sleeve in which the ports are formed -these ports cannotappreciably assist in guiding the air charge into the cylinder in thedesired direction. Further where, as, is generally preferred in sleevevalve engines, the sleeve has. a combined oscillating and reciprocatingmotion, the bar-likeparts extending betweenthe adjacent ports in thesleeve cause some obstruction to the flow of the scavenging air,.sincethesleeve tary movement of the air in an engine of the.

above general type may. be eflected';

. To this end in an internal combustion engine of the liquid-fuelinjection compression ignition type operating on the'two-stroke cycleaccording to the present invention, there is combined with a cylinder, asleeve valve controlling exhaust ports and having a part or parts formedintegral- 1y therewith or attached thereto in which are formed inlet orscavenging passages which are so shaped and of such efl'ective length asto cause tersgthebzcylindeleinsth "an reeti movemith thesleeveival'entitnesleeye the scavenging charge flowing therethrough to enter thecylinder in a direction which will tend to cause the charge to rotateabout the cylinder the passages which direct the charge has that part inwhichthe of ports B in the sleeve valve which register with "the exhaustports in thecylinder wall during the wees? leading to the ports areformed in this thickened I part. For example, the sleeve maybe formedwith a thickening in the form of a circumferential belt in which thescavenging passages *are formed. Further, in this case, the mechanismfor operating the sleeve valve .conveniently acts either on thethickened part thereof or on a portion 01' the sleeve. adjacent to thisthickened part. C

- The movement imparted to the sleeve may vary. but'th'e invention isparticularly applicable to engines of the kind in question in which thesleeve valve has imparted to it a combined oscillating and reciprocatingmovement, for example by means of a member rotating about an axis atright angles. to the cylinder axis and connected at a point eccentricwith respect to such axisoi,

rotation to the sleeve through a self-aligning joint orlike flexibleconnection. The invention may be carried into practice in 'variouswayszbut one construction according to the invention as applied to adouble-acting twostroke engine having a cylinder provided withscavenging ports'or a scave in air belt adjacent to the centre of itslength and communicating with scavenging passages in the sleeve whichservetoadmitascavensi airchargetoeach working chamber in turn as theyare uncovered respectively by the two ends of the piston, is illustratedsomewhat diagrammatically by way oi example in the accompanying drawing,in which Figural is aisectional elevation, and Figure2isasectionintheplane-2-2ot Figure 1.

In the construction illustrated, the engine comprises a' cylinder'Acontaining a sleeve valve 13 and closed at its ends by plug-likecylinder adjacent to the inner end of. each plug-like cylinder walladjacent to the inner end ofeach'pluglikecylinderhieadisaringoiexhaustportsA adapted to cooperatewith a corresponding ring scavenging period.- The cylinder A is soformed as to provide approximately midway in its length a scavengingbelt A which eral direction of each of which is tangential with respectto a circle having for centre the axis of the cylinder so that the aircharge entering through these passages will tend to rotate about thecylinder axis. Air may be deliveredunder pressure to the scavenging beltA'-'.

Formed on or in the thickening or belt 3* is a socket 3* in which ismounted the outer memher E of a self-aligning joint or hearing the innermember E of which is engaged ,by a crank pin F or the like on a smallcrankshaft F the axis cylindrical form having a diameter less than Liland, for example, approximately three-fifths of that of the sleeve B,while its depth, measured in a direction parallel to the cylinder axis,is con- ,siderablyJessthan its'diameter and may be, for example,approximately one-third of its diameter. The end of the circumferentialwall of each combustion chamber- G remote from the piston isconveniently connected to the end wall by a part G having a curvedsurface so as to avoid a sharp comer where the circumferential wallmeets the end wall. 4

A fuel sprayer H is provided in the wall of. each combustion chamber andso arranged as to inject a single jet of fuel from a point in thecircumferentialwall of this chamber approximately midway between themouth of the chamber and the end of the chamber, the mean direction ofthe spray being in a plane normal to the cylinder axis and inclined atan angle of between 30 and 60 to a tangent to the circumferential wallof the combustion chamber at the point from which the spray issues; a

Reciprocating within the sleeve B is a piston J -the circumferentialportions of the end faces J of which may be somewhat chamfered as shownatJ so as to lie parallel to corresponding chamfered faces C ,.D on theparts of the cylinder heads C and D surrounding the combustion chambermouths, to which faces the-chamfered faces J on. the piston closelyapproach at the ends of the piston strokes. The piston J is connected toa piston rod J which passes out through a suitable gland J in the lowercylinder-head D so that the piston rod J fills the centre .part of thecombustion chamber G in such cylinder head and gives to this combustionchamber an annular form.

The, operation of the engine is as follows:- Assuming the piston J to beat one end of its stroke so that it has compressed an air charge intothe combustion chamber G at the-end of the cylinder remote from thepiston rod J3, the sleeve valve B then occupies the position in whichthe exhaust ports A B at the end of the cylinder adjacent to the pistonrod J are open, while the scavenging passages B in the thickenedbelt Bare uncovered by the face of the piston J adjacent to the piston rod Jscavenging air thus enters through the scavenging ports B in such amanner as to rotate about the cylinder axis and forces the gases burntduring the last working stroke out through the open exhaust ports A Band thus fills the end of the cylinder adjacent the piston rod with afresh air charge which rotates about the cylinder axis. The piston nowisomers.v

moves under the action of the expansion of the B in "the end of thecylinder adjacent to the'piston rod J whereupon continued movement ofthe piston compresses the fresh rotating air charge into the lowercombustion chamber G adjacent to the piston rod J so that substantiallythe whole of the charge is compressed into this combustion chamber atthe end of ,the stroke.

At the end of the piston stroke, when the piston is in its lower deadcentre position, the face of the pistonJ remote from the piston rod Juncovers therscavenging ports B and the sleeve valve opens the exhaustports A B at the upper end of the cylinder remote from the piston rod sothat the burnt gases are expelled from the upper end of .the cylinderand such end of the cylinder is refilled with a fresh rotatingaircharge. At the same time fuel is injected into the lower combustionchamber G adjacent to the piston rod and the expanding gases force thepiston away from such combustion chamber to compress the fresh rotatingcharge which has been admitted into the upperend' of the cylinder, thecycleof operations described above being repeated.

It is to be understood that the construction more particularly.described above is given by passages so formed in this thickened part asto,

to rotate about the cylinder axis.

- 2; In an internal combustion engine of the liquid fuel injectioncompression ignition type operating on the two-stroke cycle, thecombination with a cylinder having a scavenging belt constituted by acircumferential recess extending completely around the cylinder, of asleeve valve having an external annular thickening extending-around thatpart which lies within the scavenging belt with scavenging passages soformed through this annular thickening as to tend to cause a charge onentering the cylinder to rotate aboutthe cylinder axis. 4 g

3. In an internal combustion engine of the liquid fuel injectioncompression ignition type as claimed in claim 1, the combination withthe sleeve valve, 'of operating mechanism for this valve acting on aportion of the sleeve connected with this thickened part.

4. In an internal combustion engine of the liquid fuelinjection-compression ignition type as claimed in claim 2, thecombinationwith the thickened part of the sleeve, of a part carried by arecess in this thickened part, a; member, rotating about an axis atright angles to the axis of the sleeve, and means for connecting thisrotary member at a point eccentric with respect to its axis of rotationto the part carried by the recess in the thickened portion so as toimpart to the sleeve 9. combined oscillating and reciprocating motion.

5. In an internal combustion engine of the liquid fuel injectioncompression ignition type, operating on the two-stroke cycle, thecombination with a cylinder, of a sleeve valve having a part in whichare formed inlet or scavenging passages so shaped and of such efiectivelength as to tend to cause a charge on entering the cylinder to rotateabout the cylinder axis, said scavenging passages being controlled onlyby the piston and being uncovered thereby at the end of each workingstroke, and exhaust ports situated at the end of the working chamber ofthe engine remote from the scavenging passages and con trolled by thesleeve valve.

6. In an internal combustion engine of the liquid fuel injectioncompression ignition type operating on the two-stroke cycle, thecombination with a cylinder having a scavenging port, of a sleeve valvehaving an external thickening provided with passage-ways therethrough,the longitudinal axis of each passageway forming an angle with thatdiameter of said cylinder which passes through the passageway concerned.

7. In an internal. combustion engine of the liquid fuel injectioncompression ignition type as claimed in claim 1, the combination withthe sleeve valve, of operating mechanism for this valve acting in thethickened part thereof.

8. In an internal combustion engine of the liquid fuel injectioncompression ignition type operating on the two-stroke cycle, thecombination with a cylinder having a scavenging belt constituted by acircumferential recess extending completely around the cylinder, of asleeve valve having an external annular thickened portion extendingaround that part which lies within the scavenging belt with scavengingpassages so formed through this annular thickened portion as to tend tocause a charge on entering the cylinder to rotate about the cylinderaxis, and operating mechanism for said valve acting on the externalannular thickened portion.

9. In an internal combustion engine of the liquid fuel injectioncompression ignition type operating on the two-stroke cycle, thecombination with a cylinder, of a piston operable in said cylinder, asleeve valve having a part in which are formed inlet or scavengingpassages so shaped and of such effective length as to tend to cause acharge on entering the cylinder to rotate about the cylinder axis, saidcylinder being formed to provide at least one air passage in constantcommunication with said scavenging passages, whereby said scavengingpassages are controlled solely by said piston.

HARRY RALPH RICARDO.

